Reading winger Garath McCleary was the target of alleged racist abuse during their FA Cup victory over Bradford City.
McCleary set up Hal Robson-Kanu's opener before scoring the second goal after nine minutes in the 3-0 win.
The incident is believed to have occurred before half time, when McCleary collected the ball for a Reading corner.
"An incident was reported to the match officials just before half time, who in turn told Reading staff. A man was then arrested and ejected during the half time interval," Reading said in a statement.
A man was arrested at half time and ejected from the stadium.